xfce4-desktop: fix builds on NetBSD 9.x

There's a parsing bug triggered in older GCC versions, e.g., 7.5.
(Probably the same one that led to the tests in libxfce4windowing
being disabled from builds, too.) Since GCC 10 already gets pulled
into the dependency chain anyway (from shared-mime-info, of all
things), go with it.

Author: dhgutteridge

x11/xfce4-desktop/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.118 2026/01/27 08:41:07 wiz Exp $
+# $NetBSD: Makefile,v 1.119 2026/03/09 21:14:44 gutteridge Exp $
 
 .include "../../meta-pkgs/xfce4/Makefile.common"
 
@@ -13,6 +13,8 @@ HOMEPAGE=	https://docs.xfce.org/xfce/xfdesktop/start
 COMMENT=	Xfce desktop background manager
 
 USE_LANGUAGES=	c99
+# Work around parsing bug triggered in older GCC versions, e.g., 7.5.
+GCC_REQD+=	10
 USE_TOOLS+=	gdbus-codegen
 
 BUILD_DEFS+=		PKG_SYSCONFBASE